• Our new ticketing site is now live! Using either this or the original site (both powered by TrainSplit) helps support the running of the forum with every ticket purchase! Find out more and ask any questions/give us feedback in this thread!

GWR Class 800

Status
Not open for further replies.
8

800001

Established Member
Joined
24 Oct 2015
Messages
7,307
Bornin1980s said:
I was of the understanding that they were limited to 100 mph in diesel mode. Does that limit not apply when the engines are used at their full rating? I once read that HST's can reach maximum speed with just one working engine (half power), but acceleration is seriously affected.

Also, it seems we've reached a bit of an impasse in diesel engine development, as these 21 L engine seem to struggle to produce more power than a Cummins 19 L engine of nearly 20 years ago. In the 50s, 60s and 70s, engine seemed to get more powerful every two years. Is it that pollution laws have limited development in that direction since then?

I do not think an engine under every vehicle is the answer. We've been enduring that for too long. That said, the use of electric transmission instead of hydro mechanical transmission should make the power cars more comfortable than conventional DMU cars.



Can you access these footpaths by rail? Also, I will be going to Exeter between Monday and Thursday next week. I won't have much time for train watching, but does anyone here know when they are likely to pass through Exeter next week, if at all?
Click to expand...

Both Footpaths easily accessible from Heighington Railway station......however during the day it is a 2 hourly service on the branch line.
 
Sponsor Post - registered members do not see these adverts; click here to register, or click here to log in
R

RailUK Forums

J

jyte

Member
Joined
27 Oct 2016
Messages
671
Location
in me shed
Clarence Yard said:
Not quite. The original timing/fuel test in January was done at 700kW, 110 mph max and the acceleration was at 0.82. This showed that HST point to point timings could nearly be matched but the engine torque was all over the place. Fuel consumption was good, in excess of what could be expected by the contract limits.

The recent three test runs were done with the set able to go above 110 mph (thanks to the ATP being signed off) but with the acceleration set at the favoured 0.7. At 565kW it was anaemic and leaving them like that would end up with worsened journey times to/from Bristol and South Wales compared with an HST.

At 700kW it got to 120mph and (give or take the odd half minute) kept to the HST point to points. At 700kW with one engine out it struggled to 105mph and would have caused operational headaches if it did it in traffic. In all three tests the engine torque was more constant within each test but obviously varied between tests.

The fuel consumption in each test was good and as a result FG are pressing the contracting parties to have the contract fuel mileage limit raised. The contract talks between the DfT and Agility to have the engines set at 700kW are apparently still ongoing. Introduction day is still 16th October, at the moment.
Click to expand...

Many thanks for that.
 
najaB

najaB

Veteran Member
Joined
28 Aug 2011
Messages
33,590
Location
Scotland
Bornin1980s said:
Also, it seems we've reached a bit of an impasse in diesel engine development, as these 21 L engine seem to struggle to produce more power than a Cummins 19 L engine of nearly 20 years ago. In the 50s, 60s and 70s, engine seemed to get more powerful every two years. Is it that pollution laws have limited development in that direction since then?
Click to expand...
IIRC, the engines in the 800s are capable of over 900bhp, the testing is being done at 700bhp. And they can output 900bhp while being significantly cleaner than older engines.
 
Wilts Wanderer

Wilts Wanderer

Established Member
Joined
21 Nov 2016
Messages
3,199
I would say it is incorrect to say that the DfT is pressing for a new contract 'to enable 125mph running'. Rather, the DfT has asked Hitachi to uprate the power units sufficiently to enable the existing HST end to end journey times to be achieved. Note this is not the same as achieving the HST point to points, as it also takes shorter dwell times into account.

My understanding of the recent test runs was to demonstrate the kind of running that would be required to achieve this, and to validate the proposed interim schedules. Whilst the 700kW output is theoretically capable of 125mph under average loading conditions, it is unlikely to be necessary and Hitachi will be anxious to do the minimum necessary to protect their performance and reliability under the TARA. Therefore we're likely to see a train that cruises at 110-115mph as this will likely be sufficient to meet the existing HST end-to-end timings. (And this corresponds to the actual running that was seen on the 'uprated 3 engine' test runs.) Whether the trains will be unleashed up to their full power settings in specific circumstances such as late running is another thing altogether. Personally I'm not sure I'm keen on a train that is artificially limited to achieve a contractual performance level, but that is the consequence of the way that the DfT has procured them. It will be interesting to compare this to the 802s when they start entering service in 2018.
 
Last edited:
leomartin125

leomartin125

Member
Joined
15 Nov 2015
Messages
1,058
Location
North West
E_Reeves said:
Hi,

Can anybody identify the GWR IEP(s) at Southampton today? I counted 8 cars all together, so there may be a mixture of sets, as there are no 8-car units, but may have been 9-car set (one car may have been missing or I might have miscounted).

Thanks
Click to expand...



If the IEP was white, it could be a Class 801 or 800/1 for VTEC, so may not be just for GWR.

If it was green, it may have something to do with that GWR bodyshell that wondered through the streets of Japan recently?
 
B

Bornin1980s

Member
Joined
4 Apr 2017
Messages
720
I understand the shells arrive at Teesport. In fact, I was also meaning to ask when they would be arriving there, though I understand Teesport may also be unviewable.
 
Last edited:
J

jyte

Member
Joined
27 Oct 2016
Messages
671
Location
in me shed
940 bhp,

So not that much.

...

Actually is that a lot more?

I don't nothing about train traction - I'll leave that to the experts :D
 
C

Clarence Yard

Established Member
Joined
18 Dec 2014
Messages
3,263
jyte said:
940 bhp,

So not that much.

...

Actually is that a lot more?

I don't nothing about train traction - I'll leave that to the experts :D
Click to expand...

The difference between the 565kW and 700kW is about 180bhp per engine so in a 10 car formation you would have about 1080bhp more to play with if you went full bifters at 700kW.

For those who will be operating these units, they would obviously prefer more power than less!
 
M

Martin222002

Member
Joined
6 Nov 2011
Messages
267
Location
Chesterfield, Derbyshire
Clarence Yard said:
Not quite. The original timing/fuel test in January was done at 700kW, 110 mph max and the acceleration was at 0.82. This showed that HST point to point timings could nearly be matched but the engine torque was all over the place. Fuel consumption was good, in excess of what could be expected by the contract limits.

The recent three test runs were done with the set able to go above 110 mph (thanks to the ATP being signed off) but with the acceleration set at the favoured 0.7. At 565kW it was anaemic and leaving them like that would end up with worsened journey times to/from Bristol and South Wales compared with an HST.

At 700kW it got to 120mph and (give or take the odd half minute) kept to the HST point to points. At 700kW with one engine out it struggled to 105mph and would have caused operational headaches if it did it in traffic. In all three tests the engine torque was more constant within each test but obviously varied between tests.

The fuel consumption in each test was good and as a result FG are pressing the contracting parties to have the contract fuel mileage limit raised. The contract talks between the DfT and Agility to have the engines set at 700kW are apparently still ongoing. Introduction day is still 16th October, at the moment.
Click to expand...

A very informative post Clarence Yard. One question though. When you are referring to the acceleration being set at 0.82 and 0.7 during the test, is that just how much it was reduced by (ie a fraction of it), or is that a particular measurement, like m/s2?
 
D

D1009

Established Member
Joined
22 Feb 2012
Messages
3,166
Location
Stoke Gifford
Given the date I'd have thought it could be that set which has been almost completed in Japan which has now arrived in the UK. That is guesswork on my part, not sure how long cargo ships take to get from Japan to the UK.
 
J

jimm

Established Member
Joined
6 Apr 2012
Messages
5,276
59CosG95 said:
May be one of the 800/3s that were supposed to be 801s. The Pistoia factory (Hitachi Rail Italy) is churning out the 802s; so it's equal chances for either.
Click to expand...

No chance of it being an 802 - they are still building the first three sets and they aren't due to arrive in the UK until the summer.

Three test trains (2 x 5 car, 1 x 9 car) from the fleet extension will arrive into Southampton port from summer 2017 to begin testing specific stretches of coastal track. HRE’s newly built depot at Stoke Gifford (Bristol) will maintain the trains during the test programme.
Click to expand...

Source: http://press.hitachirail-eu.com/pre...ute-a-step-closer-to-entering-service-1805662
 
spark001uk

spark001uk

Established Member
Joined
20 Aug 2010
Messages
2,385
So let me get this right, 800/3 (was 801) are to be the electric only units? And will they be 5 or 9car? Or both??
 
Status
Not open for further replies.

Top